miniature and instrument ball bearings P RODUCTS AND E NGINEERING

Transcription

1 miniature and instrument ball bearings P RODUCTS AND E NGINEERING

2 Welcome to the Precision Division of NHBB Since 1971 our modern manufacturing facility here in Chatsworth has been the leader in applying volume production methods to sophisticated, non-standard, ultra precision miniature and instrument bearing designs. Our position of leadership is maintained through the application of advanced technologies, significant investment in automated tooling for machining, grinding, assembly and testing, and unsurpassed process control systems. The reputation NHBB has achieved for quality, cost-effective products has earned us the confidence of customers throughout the world. As the front-runner in high-speed miniature bearing design, the Precision Division has pioneered the first mass-production of autoclavable dental bearings using a polyamide-imide retainer material, as well as the finest quality miniature gyro spin bearings. Initiatives such as ISO 9002 ensure the Precision Division s advanced capabilities will be maintained at leading edge levels. The Precision Division s multi-million dollar facility renovation includes the addition of a Class 1000 clean room for all bearing assembly. We are committed to the research and development of new materials, innovative high-performance bearing design, and the continuous improvement of existing products.

3 PART NUMBERING Part Numbering System EXAMPLE: SSRI-418ZZEEA62HA5CXXP25L02P RIF-1438FA7P13LG49U GROUP 1 MATERIAL GROUP 2 TYPE GROUP 3 BASIC SIZE GROUP 4 SEALS & SHIELDS GROUP 5 MODIFICATIONS GROUP 6 DUPLEX PAIRS GROUP 7 PREMIUM FEATURES GROUP 8 CAGE SS RI RIF ZZ EEA62 H F SS=AISI stainless steel (440C) No Code=Chrome alloy steel (52100) CE=Chrome alloy steel rings (52100) with ceramic balls SB=440C Modified SE=AISI stainless steel rings (440C) with ceramic balls ST=AISI stainless steel rings (440C) with TiC coated balls XT=Chrome alloy steel rings (52100) with TiC balls RI, R, L=Radial RIF, RF, LF=Flanged radial F=Flanged, tapered O.D. FR=Duplex pair with one flanged and one unflanged bearing RIFW, RFW, LFW =Flanged with non-standard flange width MBRI, MBR, MBL =Inner ring relieved and separable MBRIF, MBRF, MBLF=Inner ring relieved and separable, flanged outer ring MDRI, MDR, MDL =Inner ring relieved and non-separable MDRIF, MDRF, MDLF=Inner ring relieved and non-separable, flanged outer ring MERI, MER, MEL=Outer ring relieved, and non-separable MERIF, MERF, MELF=Outer ring relieved, flanged and non-separable MBF=Inner ring relieved and separable, outer ring flanged and O.D. tapered MDF=Inner ring relieved and non-separable, outer ring flanged and O.D. tapered Special Size Series: Z=(Followed by letter and numbers indicates End Bell) RA =Pulley type assemblies; shaft assemblies; mechanical parts; tape guides; special bearings Inch Series First one or two digits indicates O.D. in 16ths of an inch. The following two or three digits indicate the bore size in a fraction of an inch, the first digit being the numerator and the second or the second and third digits being the denominator. Metric Series First two digits indicate O.D. in mm. Second two digits indicate I.D. in mm. X=(following basic size) Indicates special internal design, assigned in numerical sequence i.e. X1, X2, etc. Enclosures Z=Single metallic shield-removable ZZ=Double metallic shield-removable ZO=Single shield on side opposite flange D=Single rubber seal DD=Double rubber seal D1=Single viton seal DD1=Double viton seal L=Single glass reinforced PTFE seal LL=Double glass reinforced PTFE seal LO=Single seal on side opposite flange LZ=Glass reinforced PTFE seal and shield with seal on flange side ZL=Shield and glass reinforced PTFE seal with shield on flange side DZ=Rubber seal and shield L(L) BP=Glass reinforced PTFE seal(s) with metal backing plate(s) H=Single metallic shield non-removable HH=Double metallic shield non-removable S=Single rubber seal, non-contact SS=Double rubber seal, non-contact Q(Q)=Glass reinforced PTFE seal(s), lip riding Q(Q)4=Glass reinforced PTFE seal(s) with protective shield(s), lip riding DO, QO=Single seal on side opposite flange Extended Inner Ring EE=Both sides E=One side Special External Dimension A =Larger than standard O.D. A=Semi-standard, larger width and O.D. bearing A =Larger O.D. than standard and special width W=Wider than standard width Y=Narrower than standard width N=Larger or smaller bore than standard G=Special external groove in bearing B=Special bore tolerance Special Design SD=Special design bearing CV=Special race curvature Duplex DB=Back-to-back configuration DF=Face-to-face configuration DT=Tandem configuration DU=Universal duplex. Numbers following letter code indicate mean preload in pounds. If not followed by a number, standard preload is applied. MC=Premium ball & race finish for specific applications CR=Ribbon PTFE coated F=Full ball complement H=Crown, land piloted J=Crown, acetal JM=Full type, acetal JN=Full type, molded acetal KB=Crown phenolic, paper base KC=Crown, phenolic, linen base KF=Crown phenolic, linen, non keyhole type outer land piloting KG=Crown phenolic, paper base, outer land piloted KM=Full type, phenolic, linen base KN=Full type, phenolic, paper base M4=Full type, polyimide M5=Crown, polyimide R=Ribbon, land piloted RD=Ribbon,ball piloted SL=Slug, PTFE T1=Crown, specialty material TT=Toroids, PTFE 2

4 PART NUMBERING GROUP 9 ABEC TOLERANCE GROUP 10 DIMENSIONAL CODING GROUP 11 RADIAL PLAY GROUP 12 TORQUE GROUP 13 LUBRICANT GROUP 14 PACKAGING A5 A7 CXX P25 P13 LO2 LG49 P U A1=ABEC 1* A3=ABEC 3, 3P A5=ABEC 5, 5P, 5T A7=ABEC 7, 7P, 7T A9=ABEC 9, 9P Note: Selected ABEC 9 tolerances are available on all sizes. Please consult factory. *A1 miniature and instrument bearings of both the metric and inch configurations meet the tolerances of ABMA Standard 20 for ABEC 1 metric series bearings. CXX=I.D. and O.D. calibration in.0001 increments COX=O.D. coding only,.0001 increments CXO=I.D. coding only,.0001 increments C44=I.D. and O.D. calibration in increments C04=O.D. coding only, increments C40=I.D. coding only, increments P=Followed by two,three, or four numbers indicates the radial play limits in ten thousandths of an inch. Example: P25 indicates radial play of.0002 to PC =Nominal contact angle in degrees PA _ =Nominal axial play Example: PA015 indicates axial play of.0015 T=Followed by a number indicates maximum starting torque in hundreds of mg. mm. Example: T15 indicates a maximum starting torque of 1500 mg. mm. RT=Followed by a number indicates maximum running torque in hundreds of mg. mm. Example: RT15 indicates a maximum running torque of 1500 mg. mm. Lubricant letter codes are followed by a number to indicate specific type. BC=Following lubricant code indicates barrier coating LB=Mixture of oil and solvent LD=Dry--no lubrication LF=Dry film LG=Greases LM=Mixture of oil and grease LO=Oils LY=Expanded list of oils and greases No Code=Plastic sealed vial B=Individual boxes E=Individual pack per MIL-B K=Kraft foil package KB=Kraft bag and box P=Pill pack PB=Pill pack and box U=Unit pack UB=Unit pack and box Grease Plate Code (follows lubricant code) GPL=light GPM=medium GPH=heavy IMPORTANT NOTE: The NHBB numbering system identifies ball bearing size and design. This system is not a guide to create a customized ball bearing. Please use the numbering system to decipher the basic bearing numbers listed in this catalog, or to define a number given to you by a representative of NHBB. Please consult a member of the NHBB sales or engineering staff to help you design a new bearing or to interchange another manufacturer s part number. 3

5 BASIC TECHNICAL INFORMATION Ball Bearing Components This exploded view of a standard ball bearing can help you select the bearing with the appropriate components for your design or application. The cross-sectional view illustrates the relative position of these components in the ball bearing assembly. Basic Dimensions The dimensions and reference codes used throughout this catalog are illustrated and defined below. These dimensions establish bearing size and other parameters which can help you choose the ball bearing best suited to your application. Exploded view of ball bearing Cross section view of ball bearing SNAP RING O.D. Chamfer Bearing Width SHIELD Double metallic shields reduce contaminants and lubricant leakage. CAGE Two-piece Ribbon (R); or Crown (H). Outside Diameter (O.D.) I.D. Chamfer PTFE Seal Inside Diameter (Bore) BALLS Grade 10 standard; Grade 3 or 5 also available. Stainless Steel Shield Snap Ring Precision Ball Stainless Steel Crown Cage INNER RING Usually made of either stainless steel or chrome alloy steel, both heattreated for hardness. OUTER RING Usually made of either stainless steel or chrome alloy steel, both heattreated for hardness. SHIELD Rubber and PTFE seals also available. SNAP RING Df Lo r Bo Bi r r d Li Lo d Li D r D d - Inside Diameter or Bore D - Outside Diameter O.D. B - Overall Bearing Width B i - Inner Ring Width B o - Outer Ring Width D f - Flange Outside Diameter B f - Flange Width or Thickness L i - Inner Ring Land Diameter L o - Outer Ring Land Diameter r - Maximum Shaft or Housing Fillet Radius that bearing corners will clear Z - Number of Balls per row D b - Nominal Diameter of Balls Nmax - Maximum Speed/rpm fn - Cage and Lubricant Factor. See pg. 39 Bf B 4

6 BASIC TECHNICAL INFORMATION Special Assemblies & Components Today s high-technology products demand increasingly critical tolerances. NHBB stands ready to support your needs with: Next-level bearing assemblies & subassemblies Ultra-precision components Leading edge automated production techniques Complete in-house manufacturing ISO 9002 Quality System approval 50 years of experience in precision manufacturing and assembly Our experienced staff can help you design quality, costeffective subassemblies for your specific applications and manufacture them in small or volume production quantities. NHBB can provide complete manufacturing and assembly for a wide variety of special designs. Spindle Assembly. Designed with compression coil spring shaft rotation. Integral Super Duplex. Manufactured with outer raceway ground into housing. Typical Tape Guide. Design uses screw and washer to solidly preload by clamping inner rings outer ring rotation. Special Assembly. Manufacture and assemble several components to control proper fit and performance. Shaft/Housing Assembly. Factory assembled to control fit ups and runouts. 5

7 BASIC TECHNICAL INFORMATION Bearing Selection To ensure optimal speed and load carrying capacity, several factors must be considered when choosing the proper bearing for your application. These factors include the ring material, design, shields & seals, cage, ABEC grade, radial play, and lubricant. Materials Miniature and instrument bearings are normally made of either stainless steel or chrome alloy steel. NHBB offers 440C stainless steel for applications that require corrosion resistance, and chrome steel for maximum fatigue life. These materials are heat-treated to achieve optimum hardness and dimensional stability, and are suitable for most applications. Design The design of a bearing is critical in determining its load-carrying capability and maximum operating speed factors which directly impact the bearing s operating life. Various types of bearings have been designed to meet the operating parameters of your application. The radial or conrad bearing (also referred to as deep groove) is the most popular type due to its ability to handle radial and thrust loads in either direction. This type is offered with various seal or shield options. Shields and Seals Shields and seals are used in ball bearings to retain lubricants and prevent particulate contamination from reaching the critical surfaces. Shields are popular for most applications; seals are used where minimal clearance to light contact is required. Seals offer greater deterrence to particulate contamination, but increase torque and limit operating speed. NHBB offers a variety of enclosure options. The chart on page 34 in the Engineering Section describes these options in greater detail. Cages The cage, also referred to as the retainer or separator, is the component that separates and positions the balls at approximately equal intervals around the bearing raceway. Proper selection of a bearing cage is critical for meeting the load, speed and temperature requirements of your application. The standard cages for radial or conrad miniature and instrument ball bearings are stamped metal ribbon or crown. The application flexibility and low-cost design of these types make them appropriate for most general purpose applications. For high-speed applications, machined cages made of phenolic, polyamide-imide and other materials are available. Refer to page 33 in the Engineering Section for more details on cage options. The angular contact bearing is designed with a relieved shoulder to allow for a greater number of balls, thereby increasing its load-carrying capability. The angular contact design also allows for the use of a full section cage which is desirable for high speed applications. This type of bearing can handle thrust loads in one direction only. 6

8 BASIC TECHNICAL INFORMATION ABEC Grade When choosing the ABEC grade, the factors to be considered are: radial and axial runout requirements; bore and O.D. fits; and audible noise level. The table below shows the bore and O.D. size tolerances and the radial runout limits for each ABEC grade. Grades 5 and 7 are preferred for most standard applications. Radial Runout ABEC O.D. Inner Outer Grade Size Ring Ring Mean Diameter Tolerance Bore O.D. 1* 0-18mm ( in.) over 18-30mm (over in.) 3P 0-30mm ( in.) P 0-30mm ( in.) P 0-30mm ( in.) P 0-18mm ( in.) over 18-30mm (over in.) *ABEC 1 miniature and instrument bearings of both the metric and inch configurations meet the tolerances of ABMA Standard 20 for ABEC 1 metric series bearings. The charts on pages provide a complete description of the tolerances controlled by the ABEC level. Normally, race finish and race geometry are superior in ABEC 5P and higher. NHBB recommends these grades for precision assemblies where low noise (mechanical or audible), minimal runout and long life are important considerations for noise sensitive applications. Radial Play Radial Play is the free internal radial looseness between the balls and the races with no load applied to the bearing in any direction. Radial play is necessary to accommodate differential thermal expansions, the effects of interference fits, and to control axial play and deflection. The chart on page 35 of the Engineering Section shows the suggested radial play for some typical applications. Lubricant There are literally hundreds of lubricants available for ball bearings; selecting the optimal one is critical. Each has a particular characteristic which makes it suitable for a specific application. Unless torque is a problem, grease is preferred for prelubrication since it is less susceptible to migration and leakage. Grease can increase bearing torque by a factor of 1.2 to 5.0 depending on the grease type and quantity used. See pages for further information. 7

9 BASIC TECHNICAL INFORMATION Marking The following figures illustrate the standard marking system used for NHBB Precision Bearing Division ball bearings per MIL-STD Shown below are the markings for 440C Stainless Steel and the markings for Chrome Alloy Steel. ABEC 5, 7 and higher tolerances Packaging NHBB s bearings are normally packaged in plastic vials, 8 or more per vial. If prelubrication or protective coating is not specified, oil per MIL-L-6085 (NHBB code LO1) will be used to prevent corrosion. Vial Pack (No Code) 8 or more per vial. Pill Pack (Code P) One bearing per sealed, plastic compartment. Connected in strips of 4. Unit Pack (Code U) Individual bearing placed in a plastic bag; bag is sealed; 10 or more packed in a paperboard box. Other packaging options are available to suit your specific needs. See page 3 for more information. 440C ABEC 1*, 3 and 3P tolerances 440C *ABEC 1 miniature and instrument bearings of both the metric and inch configurations meet the tolerances of ABMA Standard 20 for ABEC 1 metric series bearings. 8

10 CAPABILITIES PRODUCT QUALITY IS OUR FIRST PRIORITY DEDICATION TO QUALITY EXPERT ENGINEERING STATE-OF-THE-ART EQUIPMENT The Precision Division meets the requirements of ISO 9001:2000 and was registered to ISO 9002 in Our quality systems meet the requirements of MIL-Q-9858A and MIL-I Our computerized calibration system meets the requirements of ANSI/NCSL Z All bearings are assembled in a Class 1000 clean room environment. 100% Anderonmeter (dynamic noise and vibration) testing is standard on all of our bearing products.

11 CAPABILITIES VOLUME PRODUCTION OF SPECIALTY BEARINGS The Precision Division s specialty is volume production of ultra precision miniature and instrument bearings. Additionally, we provide facilities to develop and incorporate special materials and lubricants to meet the stringent requirements of leading-edge applications. NHBB has developed many bearing types using the latest technologies including ceramic and TiC balls, dry films and advanced lubrication strategies. We also have the capability to produce precision sub-assemblies and cylindrical components. Miniature & Instrument Bearings Precision Division Hybrid Ceramic Bearings Precision Division HiTech Division Ultra Precision Machine Tool Bearings HiTech Division

12 CAPABILITIES ONGOING NEW PRODUCT DEVELOPMENT Rod Ends, Sphericals and Link Assemblies Astro Division Cylindrical Roller Bearings HiTech Division The NHBB organization offers our customers complete access to our full range of corporate capabilities, including custom bearing design and manufacture. Just ask your contact at the Precision Division to help you reach our HiTech or Astro Division engineers as early as possible in the product design phase. At Precision, we are here to help you our valued customer. Racing Series Bearings Astro Division

13 ENGINEERING Missile/Space Guidance Systems, Propulsion Systems, Gear Motors... Aircraft Instruments, Environmental Systems, Fuel Controls, Actuators... Dental/Medical Handpieces, Centrifuges, Diagnostic Equipment, Laser Articulating Arms... PRODUCT OFFERING Ultra Precision Miniature and Instrument Bearings Hybrid Ceramics Airframe Control Duplex Pairs Thinex Industrial/ Computer Motors, Flow Meters, Storage Devices, Semiconductor Processing, Scanners... PRECISION DIVISION OF NEW HAMPSHIRE BALL BEARINGS, INC Independence Avenue Chatsworth, California TEL: (818) FAX:(818) visit us at